BEIJING (AP) — A Taiwanese academic says he was turned away by Hong Kong immigration officials after he flew to the territory to speak at a conference commemorating the 25th anniversary of the Tiananmen Square pro-democracy movement.

Tseng Chien-yuan said he was told Friday morning that the central government in Beijing had issued an order banning him from the city. Hong Kong is a former British colony that retains its own laws and civil liberties, but mainland China controls immigration and external security.